Abstract: System, apparatus, article of manufacture, method and/or computer program embodiments are provided for customizing user interfaces (UIs) based on custom themes and animations. An example method can include determining topic candidates for a theme of a UI of an application at a device associated with a user; determining a respective selection parameter for each topic from the topic candidates, the respective selection parameter comprising a topic preference score, a topic priority, a topic metric, and/or a topic relevance to a date associated with a presentation of the UI, the user, the application, and/or content associated with the application; selecting a topic from the topic candidates based on the respective selection parameter for each topic from the topic candidates; based on the topic, determining a theme for the UI of the application; and generating UI data defining a customized configuration of the UI based on the theme.